Field of the Invention
The present invention relates to a turbomachine rotor of the type comprising a disk having a plurality of annular ribs which project radially outwardly from the periphery of the disk and define a plurality of annular grooves extending around the periphery, and a plurality of blades which are secured to the disk, the blades being evenly distributed around the periphery of the disk and extending radially therefrom, and each blade having a notched root defining a plurality of heels which fit into respective grooves of the disk.
In particular the invention relates to a fan rotor fitted with large chord blades made of a composite material, in which the blades do not incorporate platforms and their roots have comb-type fixings.
Discussion of the Prior Art
U.S. Pat. No. 3,694,104 discloses a blade made of composite material having a notched root defining heels, each heel being provided with a metal bush defining a hole intended to cooperate with a fixing pin. The root of the blade is fixed to the ribs of the rotor disk by means of two axially offset pins, one situated on the upstream side of the blade in the plane of the leading edge and the other on the downstream side in the plane of the trailing edge.
This arrangement does not enable the pins to take up the entirety of the forces applied to the blades. Also, the added platforms interposed between the blades are required to take-up the tangential components of the forces, and they must be rigid and firmly secured to the disk by fixing screws, which increases the weight of the rotor. Furthermore, the angular offset existing between the axis of the upstream pin and the axis of the downstream pin of each blade creates difficulties in the construction of the blade and of the disk. Finally, certain pins and fixing screws are mounted from the front face of the disk, and others from the rear face. This requires the rotor to be dismounted if the blades are to be removed.